Amongst the risks which an aircraft must be able to face, there is a category of accidents known as accidents with impact without loss of control (or Controlled Flight Into Terrain CFIT). This category includes accidents during which an aircraft that can be flown under the control of its crew unintentionally collides with terrain, obstacles or a stretch of water without the crew being aware of the imminence of the collision.
To limit the risk associated with controlled flight into terrain accidents, new supervision instruments have been developed. Notably it is possible to cite the Terrain Awareness and Warning System. A terrain awareness and warning system may notably comprise a display device to warn the aircraft crew of the possible risks associated with the terrain. Usually, the various zones of the terrain overflown are displayed with a color code on a navigation screen. The zones presenting no particular risks for the aircraft are displayed in black, the zones presenting a low risk in green, the zones presenting a medium risk in yellow and the zones presenting a high risk in red.
The terrain awareness and warning systems may also be supplemented by a function for predicting collisions with obstacles, such as for example man-made obstacles of the electric line type or else of the very high building type. The aircraft crew must therefore have a means for being aware of the obstacles present in the environment of the aircraft in addition to information on the corresponding terrain. Warnings of different levels are able to be generated for each obstacle presenting a risk for the aircraft by the obstacle collision prediction function. These warnings must therefore also be able to be communicated to the crew by a given interface.
However, it is essential to optimize the number and pertinence of the information transmitted to the aircraft crew. This is particularly true for the obstacle-related information and warnings. Specifically, the number of obstacles in certain geographic zones is potentially high. It is therefore of no use and even dangerous to swamp the crew with items of information that are redundant and/or unusable because they are too numerous.